Davinci Jr Repetier Port (Page 6 of 9)

you think it could damage U2 to flashU17?
U2 rx go to U17 tx and U2 tx go to U17 rx, so in theory U2 should ignore informations from header if connections are made to communicate with U17

JACKPOT!

I found a page from DuetWifi that describes how to connect a display daughterboard that uses the same kind of sub/slave microcontroller relationship:

https://duet3d.com/wiki/Connecting_an_L … a_PanelDue
https://miscsolutions.wordpress.com/paneldue/

There should be some source code in the firmware related to PanelDue that we could cannibalize to work for the components our board uses.

More good news. Found J113 to be a jtag header. Check table 6-1 on page 23

Only thing that's missing is a TDI pin on the header. It looks like this is on pin 104 of U2, which is attached to a test point on the back of the board, but nothing else. It may be necessary to solder an extra pin to that test point for complete JTAG access. I'm still tracing the board looking for another possible location for the TDI pin, though. As Luc already found, TP89 is the erase pin.

I've attached a PDF and the cad file for the schematic I've completed so far. I've omitted any resistors that were 0Ω (just being used as jumpers) and the various signal filter capacitors, as they aren't really needed for the context of this schematic.

Edit: Renamed pins on the headers based on research on the datasheets for those chips

Hi pyr0ball you did great job, I envy you to get such skills, my jr was stuck 1 year due to lack of info about missing pins, now when back home I can go back to code.

Kudos for TP89 is XYlentech not me, but thank you

If you can also find pins for lcd and sd it will be useful as need to write direct connection to lcd support, as you saw duet 3d use deported lcd and main board communicate with lcd using M0 and serial, so need to add direct lcd output code

you did awsome breakthrough man, thank you

Well, the SD Card interface was easy peezy. Check table 40-2 on page 1096

I'll poke at the pins to double check if that's the actual pinout

For SD I would be surprised they followed the specsheet, they used different SD pin on their due based board
also they like to encrypt everything they can to makereverse engineering harder...

OK here's the pinout for the SDCard and the LCD:

LCD (J6 LCM):
Con_Pin | MCU_Pin | MCU_SYM
1          | +5V        | N/A
2          | GND        | N/A
3          | 111         | PC18
4          | 82           | PC8
5          | U1_Pin1   | N/A
6          | 11           | PC0
7          | 38           | PC1
8          | 39           | PC2
9          | 40           | PC3
10        | 41           | PC4
11        | 58           | PC5
12        | 54           | PC6
13        | 48           | PC7
14        | 90           | PC10
15        | 34           | VDDCORE
16        | 32           | PA21/PGMD9
17        | 31           | PB3
18        | 28           | PE5
19        | 27           | PE4
20        | 25           | PA17/PGMD5
21        | GND        | N/A
22        | +5v         | N/A

SD1:
Con_Pin | MCU_Pin | MCU_SYM
1           | N/C        | N/A
2           | GND       | N/A
3           | 118        | PA31 / MCDA1
4           | GND       | N/A
5           | 116        | PA30 / MCDA0
6           | GND       | N/A
7           | 129        | PA29 / MCCK
8           | +3.3V     | N/A
9           | +3.3V     | N/A
10         | 59          | PA25 / PGMD13 / CTS1
11         | GND       | N/A
12         | 112        | PA28 / MCCDA
13         | GND       | N/A
14         | 70          | PA27 / PGMD15 / MCDA3
15         | GND       | N/A
16         | 62          | PA28 / PGMD14 / MCDA2

No problem at all

Let me know if there's any other pins we need to probe out. I know the "Reflow Fan" header (the fan attached to the back of the case) is also tied into U17, but I haven't traced that one yet.

We could look into probing the traces for the non-populated headers as well, since these same boards are being used in higher-end models with extra stuff like the laser diodes and cameras. I might be able to put together a little guide on how to upgrade the board by adding the missing components.

Anyhoo, actually going to the office tomorrow so I should be able to get those headers installed and start sniffing data off the serial while I wait for those programmers to arrive.

Reddit came through on helping me identify U7!

Apparently it's an inverter: TC7SZ04F

I'll add that into the schematic. Hopefully an electrical engineer can chime in and help explain how this circuit works and how we need to treat it in reference to the extruder heater

Edit check out the CMOS Inverter section of this lecture for a very math-y explanation of how this IC works.

I'm sure I can figure out the entire circuit with a couple of days dedicated research and math, but I'd love it if someone else saved me the trouble.

At any rate, I'm up way late, need to put this down and go sleep

Yep! it's got JTAG for U2, Serial Wire Debug for U17.

I ordered a couple of debug interfaces to poke at them

See my earlier post with the schematic. TDI exists but it's not attached to the JTAG header and will need to be transported from a test point on the back of the board. TDO already exists on the JTAG header

Won't really know until I can start sniffing serial traffic or get the serial debug interface going. I've got the headers installed, but I'm gonna have to wait for the programmers to arrive before I can start poking around